This invention relates to a method of solubilizing a benzotriazole using one or more thiadiazoles, particularly a 2,5-dihydrocarbyldithio-1,3,4-thiadiazole.
Benzotriazole and its derivatives (e.g. tolyltriazole) are known to be corrosion inhibitors in lubricating oils (see for example U.S. Pat. No. 4,197,210). However, one problem associated with using a benzotriazole in lubricating compositions is that the benzotriazole is a solid at room temperature, and hence, incompatible with the lubricating composition and any oil-soluble additives present therein. Accordingly, it would be desirable to have available a simple yet convenient method of solubilizing (or pre-dissolving) the benzotriazole so that it can be easily added to and used in a lubricating composition.
Various methods have been suggested for solubilizing benzotriazole and its derivatives. For example, a long chain succinimide dispersant has been used as a solubilizing agent (see Canadian Patent 1,163,998 and U.S. Pat. No. 4,855,074), as have oil-soluble alcohols such as lauryl alcohol and oleyl alcohol (see Japanese application 52024202), as have various amines (see Canadian Patent 1,163,998). However, applicants are not aware of any publications disclosing the particular method and ingredients described below.